feat(builtin): expose the new linker to node programs

If the magic --bazel_node_modules_manifest flag is passed to a nodejs_binary, we peel it off and run the linker first
This lets programs avoid having custom resolution logic.

Author: alexeagle

e2e/symlinked_node_modules_npm/WORKSPACE

@@ -11,6 +11,13 @@ local_repository(
     path = "../..",
 )
 
+# We don't really need to run TypeScript rules, but we'll encounter some during
+# the loading phase because some built-in code uses TypeScript
+local_repository(
+    name = "npm_bazel_typescript",
+    path = "../../tools/mock_npm_bazel_typescript",
+)
+
 # rules_nodejs_dev_dependencies() required since we're using local_repository for
 # build_bazel_rules_nodejs above.
 load("@build_bazel_rules_nodejs//:package.bzl", "rules_nodejs_dev_dependencies")

e2e/symlinked_node_modules_yarn/WORKSPACE

@@ -11,6 +11,13 @@ local_repository(
     path = "../..",
 )
 
+# We don't really need to run TypeScript rules, but we'll encounter some during
+# the loading phase because some built-in code uses TypeScript
+local_repository(
+    name = "npm_bazel_typescript",
+    path = "../../tools/mock_npm_bazel_typescript",
+)
+
 # rules_nodejs_dev_dependencies() required since we're using local_repository for
 # build_bazel_rules_nodejs above.
 load("@build_bazel_rules_nodejs//:package.bzl", "rules_nodejs_dev_dependencies")

internal/linker/BUILD.bazel

@@ -1,4 +1,5 @@
 # BEGIN-INTERNAL
+load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load("@npm_bazel_typescript//:index.from_src.bzl", "checked_in_ts_library")
 
 # We can't bootstrap the ts_library rule using the linker itself,
@@ -12,6 +13,12 @@ checked_in_ts_library(
     deps = ["@npm//@types/node"],
 )
 
+bzl_library(
+    name = "bzl",
+    srcs = glob(["*.bzl"]),
+    visibility = ["//visibility:public"],
+)
+
 # END-INTERNAL
 exports_files(["index.js"])
 

internal/node/node.bzl

@@ -169,6 +169,8 @@ def _nodejs_binary_impl(ctx):
         # attempts to do bazel run
         fail("The node toolchain was not properly configured so %s cannot be executed. Make sure that target_tool_path or target_tool is set." % ctx.attr.name)
 
+    node_tool_files.append(ctx.file._link_modules_script)
+
     if not ctx.outputs.templated_args_file:
         templated_args = ctx.attr.templated_args
     else:
@@ -201,6 +203,7 @@ def _nodejs_binary_impl(ctx):
         ]),
         "TEMPLATED_env_vars": env_vars,
         "TEMPLATED_expected_exit_code": str(expected_exit_code),
+        "TEMPLATED_link_modules_script": _to_manifest_path(ctx, ctx.file._link_modules_script),
         "TEMPLATED_node": node_tool_info.target_tool_path,
         "TEMPLATED_repository_args": _to_manifest_path(ctx, ctx.file._repository_args),
         "TEMPLATED_script_path": script_path,
@@ -425,6 +428,10 @@ The set of default  environment variables is:
         default = Label("//internal/node:node_launcher.sh"),
         allow_single_file = True,
     ),
+    "_link_modules_script": attr.label(
+        default = Label("//internal/linker:index.js"),
+        allow_single_file = True,
+    ),
     "_loader_template": attr.label(
         default = Label("//internal/node:node_loader.js"),
         allow_single_file = True,

internal/node/node_launcher.sh

@@ -117,6 +117,7 @@ TEMPLATED_env_vars
 readonly node=$(rlocation "TEMPLATED_node")
 readonly repository_args=$(rlocation "TEMPLATED_repository_args")
 readonly script=$(rlocation "TEMPLATED_script_path")
+readonly link_modules_script=$(rlocation "TEMPLATED_link_modules_script")
 
 source $repository_args
 
@@ -125,11 +126,17 @@ NODE_OPTIONS=()
 ALL_ARGS=(TEMPLATED_args $NODE_REPOSITORY_ARGS "$@")
 for ARG in "${ALL_ARGS[@]}"; do
   case "$ARG" in
+    --bazel_node_modules_manifest=*) MODULES_MANIFEST="${ARG#--bazel_node_modules_manifest=}" ;;
     --node_options=*) NODE_OPTIONS+=( "${ARG#--node_options=}" ) ;;
     *) ARGS+=( "$ARG" )
   esac
 done
 
+# Link the first-party modules into node_modules directory before running the actual program
+if [[ -n "$MODULES_MANIFEST" ]]; then
+  "${node}" "${link_modules_script}" "${MODULES_MANIFEST}"
+fi
+
 # The EXPECTED_EXIT_CODE lets us write bazel tests which assert that
 # a binary fails to run. Otherwise any failure would make such a test
 # fail before we could assert that we expected that failure.

tools/mock_npm_bazel_typescript/BUILD.bazel

@@ -0,0 +1 @@
+workspace(name = "npm_bazel_typescript")

tools/mock_npm_bazel_typescript/WORKSPACE

@@ -0,0 +1,6 @@
+"Minimal implementation to make loading phase succeed"
+
+def noop(**kwargs):
+    pass
+
+checked_in_ts_library = noop